1. Field of the Disclosure
This disclosure relates to an organic electro-luminescence display device, and particularly to an organic electro-luminescence display device, and a manufacturing method thereof.
2. Description of the Related Art
As the information society grows, flat display devices capable of displaying information have been widely developed. These flat display devices include liquid crystal display (LCD) devices, organic electro-luminescence display (OLED) devices, plasma display devices, and field emission display devices.
Among the above flat display devices, the OLED devices can be light and thin because they do not need backlight units required by the LCD devices. Also, the OLED devices are manufactured through simple processes in comparison with the LCD devices so that they cut down their manufacturing costs. Moreover, the OLED devices have several features such as a low voltage drive, a high luminous efficiency, a wide viewing angle. Accordingly, the OLED devices have caught more of the attention as one of next-generation display devices.
The OLED device has a configuration such that a drive element and an organic light emission diode element are formed on a single substrate. Due to this, their manufacturing processes are complicated, thereby causing more of the manufacturing defects. To address this shortcoming, another configuration wherein the driver element and the organic light emission diode element are formed on substrates different from each other has recently researched and developed.
FIG. 1 is a cross sectional view showing schematically an OLED device of the related art. Referring to FIG. 1, a first substrate 1 has a driver element 2 thereon and a second substrate 3 has an organic light emission diode element 4 formed thereon. For the electrical connection of the driver element 2 and the organic light emission diode element 4, a contact spacer 5 is disposed therebetween. Moreover, a sealant 6 is disposed along the edges of the first and second substrates 1 and 3 and combines those each other. Then, a space pressure between the first and second substrates 1 and 3 is decreased to contact the contact spacer 5 with the driver element 2 and the organic light emission diode element 4.
In such a configuration of the OLED device, the driver element 2 applies a signal to the organic light emission diode element 4 through the contact spacer 5. In accordance therewith, the organic light emission diode element 4 generates lights corresponding to the signal applied from the driver element 2.
However, the internal pressure into the cavity between the first and second substrates 1 and 3 increases as time passes. Due to this, the contact spacer 5 is separated from the driver element 2 and loses contact with it. In the end, the organic light emission diode element 4 is not luminous resulting in a defect such as a black spot (or dot).
Specially, in the OLED devices which are enlarged in accordance with the size of display device, this black spot defect occurs frequently and in proportion to their greater size. As a result, some large OLED devices, which incur a high manufacturing cost, can not be used due to heavy costs.
Also, if the pressure between the first and second substrates 1 and 3 is lowered, the contact spacer 5 is in simple contact with the driver element 2, thereby deteriorating the structural strength of the OLED device.
Furthermore, moisture and/or oxygen can intrude into the OLED device through the sealant 6 and can cause performance defects of the driver element 2 and the organic light emission diode element 4. Since the organic light emission diode element 4 is very delicate under exposure to moisture and oxygen, its material characteristics deteriorate under such exposure, thereby causing a weakening in brightness, color shift, and other defects.